To work out or not to work out -- that's the question. Many people don't know the facts when it comes to exercising while ill. Some experts maintain there is some truth to the notion that working out when sick will make you feel better. However, they recommend activities that increase circulation. But avoid high-intensity exercises that make you gasp. Many enthusiasts follow these guidelines: If the cold is in your head -- sneezing, runny nose, headache, etc. -- a low-intensity workout will benefit you. But if the ailment is accompanied by a chest cough, upset stomach or fever, take it easy until you're feeling better. A good rule of thumb is that it's OK to exercise when your ailments are from the neck up.